I would check the u-joint first. And, do it before driving it again. Could be that the ears are not properly nested into the trans half. Causes a lot of vibration, and if really bad , it can hit the housing and make a heckuva racket.
Other potential problem area, Motor mount, front or rear loose causing a shift under power. Unlikely, but a missing pilot bearing can cause vibration, but it will do it with the truck stationary revving the engine.
If it does it when the clutch is out, engaged, it can't be the throwout bearing as it is only turning when the clutch is disengaged.
